In Bi and Poo's experiments [1]} on spike-timing-dependent plasticity (STDP), the behavior of a pair of interconnected neurons, in which the synaptic weight is not strong enough for a presynaptic spike to cause a postsynaptic spike, is studied. The presynaptic neuron is initially stimulated to spike, and the amplitude of the excitatory postsynaptic current (EPSC) is measured. After five minutes, the presynaptic neuron is stimulated again to spike. Next, after \(\varepsilon \)  time, the postsynapse is stimulated to spike. This pair of stimulations is repeated every second for 60 seconds. Finally, after twenty minutes, the amplitude of the EPSC is measured again and the percentage change is recorded.
